Please clarify what you mean by "run time"? Are you referring to an interactivre terminal session, most likely TSO/ISPF session, where an individual is supplying input to your program?
With z/OS and SAS, it is possible to develop a SAS application and have that application work together with TSO/ISPF dialog services (or with native REXX language and CLIST), in the interactive mode.
I recommend reading the SAS z/OS Companion discussion (reference links pasted below). Also, you will find SAS technical and conference papers at the SAS support
http://support.sas.com/ website for this topic.
Scott Barry
SBBWorks, Inc.
SAS z/OS Companion - Windows and Commands in z/OS Environments
http://support.sas.com/documentation/cdl/en/hosto390/61886/HTML/default/a000165950.htm
SAS Interfaces to ISPF and REXX
http://support.sas.com/documentation/cdl/en/hosto390/61886/HTML/default/a000217153.htm